Ignore __all__ statements (pyccel#2100)

Fix translation of modules containing `__all__` by ignoring `__all__`.
The statement is still printed in the Python translation. Fixes pyccel#2099

Author: EmilyBourne

CHANGELOG.md

@@ -60,6 +60,7 @@ All notable changes to this project will be documented in this file.
 -   #2061 : Add C support for string declarations.
 -   Add support for inhomogeneous tuple annotations.
 -   #1834 : Add support for `@property` decorator.
+-   #2099 : Fix translation of modules containing `__all__`.
 -   \[INTERNALS\] Add abstract class `SetMethod` to handle calls to various set methods.
 -   \[INTERNALS\] Added `container_rank` property to `ast.datatypes.PyccelType` objects.
 -   \[INTERNALS\] Add a `__call__` method to `FunctionDef` to create `FunctionCall` instances.

pyccel/ast/core.py

@@ -41,6 +41,7 @@
 # TODO [YG, 12.03.2020]: Rename classes to avoid name clashes in pyccel/ast
 __all__ = (
     'AliasAssign',
+    'AllDeclaration',
     'Allocate',
     'AnnotatedComment',
     'AsName',
@@ -4404,5 +4405,36 @@ def name(self):
         """
         return self._name
 
+class AllDeclaration(PyccelAstNode):
+    """
+    Class representing the __all__ declaration of public methods in a module.
+
+    Class representing the __all__ declaration of public methods/variables/classes
+    in a module.
+
+    Parameters
+    ----------
+    values : iterable[LiteralString]
+        A PythonList/PythonTuple of strings.
+    """
+    __slots__ = ('_values',)
+    _attribute_nodes = ('_values',)
+
+    def __init__(self, values):
+        if not hasattr(values, '__iter__') or any(not isinstance(v, LiteralString) for v in values):
+            errors.report("__all__ must be an iterable of strings.",
+                        symbol=values, severity='fatal')
+        self._values = values
+        super().__init__()
+
+    @property
+    def values(self):
+        """
+        An iterable of LiteralStrings describing the public methods/variables/classes/etc.
+
+        An iterable of LiteralStrings describing the public methods/variables/classes/etc.
+        """
+        return self._values
+
 #==============================================================================
 

pyccel/ast/datatypes.py

@@ -789,7 +789,11 @@ class HomogeneousListType(HomogeneousContainerType, metaclass = ArgumentSingleto
     def __init__(self, element_type):
         assert isinstance(element_type, PyccelType)
         if element_type.rank > 0:
-            errors.report("Nested lists are not yet fully supported. Using containers in lists may lead to bugs such as memory leaks", symbol=self, severity="warning")
+            # When this error is removed the pop() of the warning must also be removed
+            # in parser/semantic.py before the creation of the AllDeclaration node
+            errors.report("Lists of non-scalar objects are not yet fully supported. " +
+                    "Using containers in lists may lead to bugs such as memory leaks",
+                    symbol=self, severity="warning")
         self._element_type = element_type
         self._order = 'C' if (element_type.order == 'C' or element_type.rank == 1) else None
         super().__init__()

pyccel/codegen/printing/ccode.py

@@ -2820,6 +2820,8 @@ def _print_MacroCount(self, expr):
     def _print_PrecomputedCode(self, expr):
         return expr.code
 
+    def _print_AllDeclaration(self, expr):
+        return ''
 
     def indent_code(self, code):
         """Accepts a string of code or a list of code lines"""

pyccel/codegen/printing/fcode.py

@@ -3752,5 +3752,8 @@ def _print_MacroUndef(self, expr):
         name = expr.macro_name
         return f'#undef {name}\n'
 
+    def _print_AllDeclaration(self, expr):
+        return ''
+
     def _print_KindSpecification(self, expr):
         return f'(kind = {self.print_kind(expr.type_specifier)})'

pyccel/codegen/printing/pycode.py

@@ -1006,6 +1006,10 @@ def _print_Module(self, expr):
                         body    = body,
                         prog    = prog)
 
+    def _print_AllDeclaration(self, expr):
+        values = ',\n           '.join(self._print(v) for v in expr.values)
+        return f'__all__ = ({values},)\n'
+
     def _print_PyccelPow(self, expr):
         base = self._print(expr.args[0])
         e    = self._print(expr.args[1])

pyccel/parser/scope.py

@@ -347,18 +347,21 @@ def insert_variable(self, var, name = None):
                 self.insert_symbol(name)
 
     def remove_variable(self, var, name = None):
-        """ Remove a variable from anywhere in scope
+        """
+        Remove a variable from anywhere in scope.
+
+        Remove a variable from anywhere in scope.
 
         Parameters
         ----------
-        var  : Variable
-                The variable to be removed
-        name : str
+        var : Variable
+                The variable to be removed.
+        name : str, optional
                 The name of the variable in the python code
-                Default : var.name
+                Default : var.name.
         """
         if name is None:
-            name = var.name
+            name = self._original_symbol[var.name]
 
         self._used_symbols.pop(name)
 

pyccel/parser/semantic.py

@@ -8,6 +8,7 @@
 """
 
 from itertools import chain, product
+import os
 import warnings
 
 from sympy.utilities.iterables import iterable as sympy_iterable
@@ -57,6 +58,7 @@
 from pyccel.ast.core import Decorator
 from pyccel.ast.core import PyccelFunctionDef
 from pyccel.ast.core import Assert
+from pyccel.ast.core import AllDeclaration
 
 from pyccel.ast.class_defs import get_cls_base
 
@@ -1610,8 +1612,10 @@ def _assign_lhs_variable(self, lhs, d_var, rhs, new_expressions, is_augassign =
 
                 # Not yet supported for arrays: x=y+z, x=b[:]
                 # Because we cannot infer shape of right-hand side yet
-                know_lhs_shape = (lhs.rank == 0) or all(sh is not None for sh in lhs.alloc_shape) \
-                        or isinstance(lhs.class_type, StringType)
+                if isinstance(lhs.dtype, StringType):
+                    know_lhs_shape = (lhs.rank == 1) or all(sh is not None for sh in lhs.alloc_shape[:-1])
+                else:
+                    know_lhs_shape = (lhs.rank == 0) or all(sh is not None for sh in lhs.alloc_shape)
 
                 if isinstance(class_type, (NumpyNDArrayType, HomogeneousTupleType)) and not know_lhs_shape:
                     msg = f"Cannot infer shape of right-hand side for expression {lhs} = {rhs}"
@@ -3590,6 +3594,21 @@ def _visit_Assign(self, expr):
 
             new_expressions.append(new_expr)
 
+        if expr.lhs == '__all__':
+            self.scope.remove_variable(lhs[0])
+            self._allocs[-1].discard(lhs[0])
+            if isinstance(lhs[0].class_type, HomogeneousListType):
+                # Remove the last element of the errors (if it is a warning)
+                # This will be the list of list warning
+                try:
+                    error_info_map = errors.error_info_map[os.path.basename(errors.target)]
+                    if error_info_map[-1].severity == 'warning':
+                        error_info_map.pop()
+                except KeyError:
+                    # There may be a KeyError if this is not the first time that this DataType
+                    # of list of rank>0 is created.
+                    pass
+            return AllDeclaration(new_expressions[-1].rhs)
 
         if (len(new_expressions)==1):
             new_expressions = new_expressions[0]

tests/epyccel/modules/Module_1.py

@@ -1,5 +1,6 @@
 # pylint: disable=missing-function-docstring, missing-module-docstring
 
+__all__ = ('f', 'g', 'h')
 
 def f(x : 'float [:]'):
     x[0] = 2.

tests/epyccel/modules/Module_2.py

@@ -1,5 +1,6 @@
 # pylint: disable=missing-function-docstring, missing-module-docstring
 
+__all__ = ['f6', 'h']
 
 def f6(m1 : 'int', m2 : 'int', x : 'float [:,:]'):
     x[:,:] = 0.